Ultracold mixtures of metastable He and Rb: scattering lengths from ab initio calculations and thermalization measurements

We have investigated the ultracold interspecies scattering properties of metastable triplet He and Rb. We performed state-of-the-art ab initio calculations of the relevant interaction potential, and measured the interspecies elastic cross section for an ultracold mixture of metastable triplet $^4$He and $^{87}$Rb in a quadrupole magnetic trap at a temperature of 0.5 mK. Our combined theoretical and experimental study gives an interspecies scattering length $a_{4+87}=+17^{+1}_{-4}$ $a_0$, which prior to this work was unknown. More general, our work shows the possibility of obtaining accurate scattering lengths using ab initio calculations for a system containing a heavy, many-electron atom, such as Rb.Comment: 11 pages, 11 figures, accepted for publication in Phys. Rev.

Fertilisation with ash from wood and with sewage sludge versus contents of macro- and microelements in the soil following cultivation of Helianthus tuberosus L.

The present study investigated the effects produced in the soil by municipal sewage sludge and wood ash applied during the cultivation of Jerusalem artichoke. The impact of the presence of applied the fertilizer materials on changes in soil and a macro- and microelements contents were investigated. The comparative analyses took into account 3 factors; the first factor - 4 levels of wood ash – 0; I–4.28; II–8.57; III–12.85 t ha-1, the second factor – 2 levels of sewage sludge – 0; 1 – 30.3 t ha-1, the third factor – 2 varieties of Jerusalem artichoke (Helianthus tuberosus L.) – Gigant, Albik. Application of the fertilisers did not resulted in significant change in the total contents of phosphorus, potassium and magnesium in soil examined after Jerusalem artichoke was harvested. Application of ash from coniferous trees, with high levels of calcium, resulted in increased total contents of calcium in the soil. Fertilisation of the soil with ash from coniferous trees or with sewage sludge, as well as cultivation of two varieties of Jerusalem artichoke, resulted in a significant increase in the concentrations of cadmium and lead, and produced no effects in the levels of nickel, zinc and copper identified in soil. The above findings, and in particular the fact that the limit values were not exceeded, indicate the possibility of using both sludge and biomass ash for fertilizing Jerusalem artichoke

The 2011 stripe rust epidemic in western Canada

Non-Peer Reviewe

New transit observations for HAT-P-30 b, HAT-P-37 b, TrES-5 b, WASP-28 b, WASP-36 b, and WASP-39 b

We present new transit light curves for planets in six extrasolar planetary systems. They were acquired with 0.4-2.2 m telescopes located in west Asia, Europe, and South America. When combined with literature data, they allowed us to redetermine system parameters in a homogeneous way. Our results for individual systems are in agreement with values reported in previous studies. We refined transit ephemerides and reduced uncertainties of orbital periods by a factor between 2 and 7. No sign of any variations in transit times was detected for the planets studied.Comment: Submitted to Acta Astronomic

Transit Timing Analysis in the HAT-P-32 system

We present the results of 45 transit observations obtained for the transiting exoplanet HAT-P-32b. The transits have been observed using several telescopes mainly throughout the YETI network. In 25 cases, complete transit light curves with a timing precision better than $1.4\:$min have been obtained. These light curves have been used to refine the system properties, namely inclination $i$, planet-to-star radius ratio $R_\textrm{p}/R_\textrm{s}$, and the ratio between the semimajor axis and the stellar radius $a/R_\textrm{s}$. First analyses by Hartman et al. (2011) suggest the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21ms. Thus we can exclude TTV amplitudes of more than $\sim1.5$min.Comment: MNRAS accepted; 13 pages, 10 figure

Transit Timing Analysis in the HAT-P-32 System

We present the results of 45 transit observations obtained for the transiting exoplanet HATP- 32b. The transits have been observed using several telescopes mainly throughout the YETI (Young Exoplanet Transit Initiative) network. In 25 cases, complete transit light curves with a timing precision better than 1.4 min have been obtained. These light curves have been used to refine the system properties, namely inclination i, planet-to-star radius ratio Rp/Rs, and the ratio between the semimajor axis and the stellar radius a/Rs. First analyses by Hartman et al. suggests the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also the literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21 ms. Thus, we can exclude TTV amplitudes of more than ∼1.5min